Internal spreader means for use with a reusable tie rod

ABSTRACT

A retractable, removable and reusable tie assembly for concrete forms which includes a single tie rod, and an internal spreader and spacing system which includes a sleeve means, the spreader system having built-in provisions for internal spreading and spacing of forms in such a manner as to permit the tie rod to be partially withdrawn on one side of the form facilitating the installation of the closing form, on the opposite side, and then to be inserted to engage and lock with the internal spreader system, thus keeping the two adjacent sides of the forms in a definite predetermined position apart during the concrete pour, then to be removed undamaged from the hardened concrete prior to dismantling of the forms, leaving the internal spreader in the concrete to be removed after stripping of the forms without damaging the internal spreader.

United States Patent 91 Lovisa et a1.

[ INTERNAL SPREADER MEANS FOR USE WITH A REUSABLE TIE ROD [75] Inventors: Peter R. Lovisa, Pelham; Dusan Tausanovitch, Northport, both of NY.

[73] Assignees: Peter R. Lovisa, Pelham; Dusan Tausanovitch, Northport; Tullio Lovisa, Huntington Station, all of NY. part interest to each [22] Filed: Apr. 30, 1974 [21] Appl. No.: 465,530

Related US. Application Data [62] Division of Ser. No. 232,450, March 7, 1972, Pat.

[ 51 Dec. 23, 1975 2,709,292 5/1955 Otti 249/43 3,437,309 4/1969 Tausanovitch 249/43 3,465,999 9/1969 Gates 2491213 3,746,297 7/1973 Daniels, Jr. 249/40 Primary Examiner-Robert D. Baldwin Assistant ExaminerJohn McQuade Attorney, Agent, or FirmKane, Dalsimer, Kane, Sullivan and Kurucz [57] ABSTRACT A retractable, removable and reusable tie assembly for concrete forms which includes a single tie rod, and an internal spreader and spacing system which includes a sleeve means, the spreader system having built-in provisions for internal spreading and spacing of forms in such a manner as to permit the tie rod to be partially withdrawn on one side of the form facilitating the installation of the closing form, on the opposite side,

and then to be inserted to engage and lock with the internal spreader system, thus keeping the two adjacent sides of the forms in a definite predetermined position apart during the concrete pour, then to be removed undamaged from the hardened concrete prior to dismantling of the forms, leaving the internal spreader in the concrete to be removed after stripping of the forms without damaging the internal spreader.

10 Claims, 13 Drawing Figures U.S. Patent D6C.23, 1975 Sheet3of4 3,927,856

FIG.9

US. Patent Dec. 23, 1975 Sheet 4 of4 3,927,856

INTERNAL SPREADER MEANS FOR USE WITH A REUSABLE TIE ROD This is a division of application Ser. No. 232,450, filed Mar. 7, 1972, now U.S. Pat. No. 3,822,860.

BACKGROUND OF THE INVENTION The general purpose of tie assemblies as a tensile unit is to secure forms in place against the lateral pressure of unhardened concrete.

There are three basic types of ties for concrete forms. First, a continuous single tie rod, usually equipped with two weakened break points at certain distance from the concrete forms. The external parts or ends of the ties, after the concrete is hardened, are twisted, broken at the weakened points and removed. The second type of tie is a reusable tapered tie, removed from the concrete wall in the direction of larger rod diameter. The third type of tie is an internal disconnecting tie which consists of a threaded inner part that is lost in the concrete and two removable end bolts which project through the form. In all cases, holes left in the concrete surface are plugged or patched by grout.

The first type of tie, (commonly called snap tie"), break back tie, have a smaller cross section, and a weakened section for break back and are feasible only for lighter concrete pressures. They are used with a simple wedge type holding devices, which are hammered in place for easy adjustment of the forms.

The snap ties are a single unit tie with a built-in spreader system washers, or cones, but has disadvantages in closing and stripping operations of the forms. After the first side of the form is erected and reinforcing steel is installed, the snap tie has to be inserted from the inner face of these forms through the hole in the plywood sheet. In this position snap ties project through the thickness of the future wall and in addition, about 8 inches past the face of the concrete surface. This condition creates time consuming work in matching and pushing fishing" of ties through the large number of holes on the plywood sheet when it is installed on the opposite side.

Similar difficulties exist in stripping of the forms. Usually, a form panel or plywood sheet gets stuck on the projected tie heads and long tie ends, which are nearly impossible to place exactly parallel to each other.

To overcome this, ends of snap ties are usually broken before stripping of forms. This cannot be done after the minimum required curing period of the concrete has elapsed since the ties cannot be twisted and broken because they will rotate in the still insufficiently hardened or green" concrete. Forms have to remain in place for a longer period and the reusability of the forms is decreased. Finishing can not take place while concrete is still green" or relatively soft.

The second type of tie, a tapered tie, requires a coating before each reuse, needs to be hammered or rotated, or both, after concrete is poured, which often requires overtime work. The spreader system is independent of the tie and as such is not positive and reliable. Manufacture and machining of tapered ties is expensive and, therefore, uneconomical for general use.

The third type of tie has an internal disconnecting part and two removable threaded end bolts, commonly known as coil type, and is generally used where heavier loads are required or when using large forming panels known as gang" forms. The bolt ends require screwing and the use of tools to secure them to the form which is time consuming and adds to the labor costs.

Conditions for closing and stripping of forms are much better than with a break back tie, but still represent a two man job to match and thread end bolts with intermediate threaded connection, especially for bolts out of reach, located in the middle part of large form panels.

A reusable concrete form tie is disclosed in U.S. Pat. No. 3,437,309. The tie assembly disclosed is provided with a yieldable tube with a tie rod slidably disposed therein, the tube being employed as the sleeve means between the forms. After the forms have been removed the entire assembly, including the tie rod, is removed from the concrete wall.

SUMMARY OF THE INVENTION The present invention, combines the benefits of snap ties as a single tie rod unit, but without being restricted to a small cross-section and with the benefits of removable end bolts of the 'coil type tie, thereby providing greatly reduced labor costs in the forming operation, freely retractable, easily installed and entirely withdrawn from forms in place. The removable tie rod with a remotely engaged internal spreader assembly represents an entirely new and unique type of tie, thus offering an improved technique in forming operations.

The invention herein generally contemplates the provision of a reusable tie assembly for concrete forms capable of being disassembled after use and which is readily removed from the concrete wall or structure without damage to any portion of the tie assembly. The tie assembly includes an internal spreader means adapted to be positioned between concrete forms and to provide internal spreading and spacing means as well as a passage for receiving a tie rod. The tie rod is removably mounted in the passage of the sleeve means and is provided with means defining surfaces engageable with the rod and internal spreader means so that the rod and internal spreader means are disengageable from each other after the concrete has been poured. The tie rod is removable therefrom while the forms remain in an erected position thereby permitting the stripping of the forms from the concrete without the necessity of severing tie rods or holding the forms in a position for removal from ends of tie rods embedded in the concrete and with the subsequent removal of the internal spreader means without damage. The inven tion also contemplates the provision of a novel wedge for removably mounting to the forms and adapted to releasably couple to the ends of the tie rod regardless of the plane of the tie rod passing through the concrete forms.

It is therefore an object of the present invention to provide an improved type of tie assembly which will facilitate the erection and stripping of concrete forms; which readily reduces the labor costs attendant thereto, and which can be disassembled prior to the stripping operation after the concrete structure has been formed. Another object of the invention is to provide a tie assembly which can be easily and quickly installed having a variety of uses including gang forming.

Another object of the invention is to provide a tie assembly which is relatively inexpensive to manufacture, economical to use, readily assembled and disassembled prior to and subsequent to use, with all parts being reusable. Another object of the invention is to provide wedges which are employed to anchor or rigidly mount the tie rod to the form to prevent lateral movement of the tie rod assembly after erection of the forms and which can be readily removed from the form and easily disengaged from the tie rod.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view which illustrates one form of a tie assembly of the invention herein.

FIG. 2 is an elevational sectional view of the tie assembly ready for use.

FIG. 3 is a side elevational view of a washer means for releasably mounting the elastomeric sleeve means to the tie rod of the assembly shown in FIGS. 1 and 2.

FIG. 4 is a plan view of the washer means illustrated in FIG. 3.

FIG. 5 is an exploded view of another form of the tie assembly of the invention herein.

FIG. 6 is an elevational sectional view of the tie assembly ready for use.

FIGS. 7, 8 and 9 illustrate the steps for erecting and stripping concrete forms employing the tie assembly of the invention herein.

FIG. 10 is a perspective view of the novel wedge assembly for removably mounting to the ends of the tie rod of FIGS. 1 and 5.

FIG. 11 illustrates the wedge of FIG. 10 mounted to an end of the tie rod of FIG. 5.

FIG. 12 illustrates the wedge of FIG. 10 mounted to the other end of the tie rod of FIG. 5.

FIG. 13 is a perspective view of the tie rod coupling means before being mounted to the wedge of FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding of the invention herein reference is had to the drawings and particularly to the embodiment of FIGS. 1 through 4.

Tie assembly 10 includes tie rod 12 and internal spreader means 20. Internal spreader means comprises a yieldable elastomeric tubular sleeve 21 having mounted at one end 24 a frustro conical cone 22. A passage extending through cone 22 is formed so as to be in axial alignment with the passage of tubular sleeve 21. Cone 22 is generally formed of hard rubber such as neoprene.

Cone 22 has a lower base 26 and an upper base 28 with an annular recess 30 formed therein and having a diameter substantially equal to the outside diameter of sleeve 21. The annular recess 30 facilitates mounting cone 22 on end 24 by providing contact surfaces within the annular recess for receiving a suitable adhesive so that end 24 is bonded thereto.

Cone 22 has embedded therein adjacent base 26 slotted washer 36. Slotted washer 36 is formed of a rigid material such as steel and forms part of the locking mechanism for removably mounting internal spreader means 20 on rod 12. Slotted washer 36 may be formed by a stamping procedure wherein slots 38 and 39 are formed diametrically opposite to each other. The portion of the slot which is stamped from washer 36 forms depending projections 40 and 41. Also, formed around the outer edge of base 26 is annular rim 29 which serves as a seal to prevent leakage of concrete through the holes in the forms "F".

A removable cone 23 is formed of a hard rubber material such as neoprene and is made having the same configuration as cone 22. A second steel washer 37 is embedded in the base 27 of cone 23 and may be slotted as illustrated in FIG. 4 but is preferably provided without slots. Also, a similar sealing rim 29' as formed on base 26 is provided on base 27. Formed on the lateral surface of cones 22 and 23 and adjacent their respective upper bases 28 and 28' are raised projections 22' and 23' so as to provide stop means to prevent rotation thereof when retracting or removing the tie rod 12.

Tie rod 12 is made of a material having high tensile and shearing properties such as suitable types of steel. Small projections 14 are formed on rod 12 and are positioned diametrically opposite to each other. Porjections 14 may be made by simply pressing the steel rod so as to die cut the rod to form a raised projection on each side thereof. Similarly formed projections 15 are spaced from projections 14 a distance from each other substantially equal to the length of sleeve means 20. When mounting internal spreader means 20 on rod 12 one end of the rod is passed through cone 22 and tubular sleeve 21. Cone 22 is then rotated to permit cone 22 to pass beyond raised projections 14. Then, by simply rotating cone 22 less than 180 internal spreader means 20 will be in locked position on rod 12. Then cone 23 is passed over the end of rod 12 adjacent projections 14 so that cone 23 will be mounted in position as illustrated in FIG. 2.

Formed adjacent each end of rod 12 is a pair of parallel notches 18 and 19. These notches form part of the locking assembly for removably mounting the tie rod assembly in fixed position to the forms. Parallel notches l8 and 19 in the embodiment illustrated in FIG. 1 are mounted in a steel holding device such as illustrated in FIG. 12. SUch a steel holding device or wedge is easily mounted to a fonn as illustrated in FIGS. 7 and 8.

Wedge 42 is generally rectangular in shape and is made of a malleable steel. A raised body portion in the form of an incline plane 43 having a longitudinally extending slot 44 is formed therein. At the base of slot 44 an opening 45 is provided for receiving rod 12 or 62 and also to provide an access opening for mounting tie rod coupling means 50 in slot 44. Tie rod coupling means 50 is held in fixed slot 44 by a suitable stop means 52. Thus, tie rod anchoring means 50 is slidable along slot 44 from the junction of the opening 45 to the opposite end of slot 43. The notch 46 provided in tie rod anchoring means 50 has a dimension substantially equal to the mass 17 of rod 12 defining the base surfaces of parallel notches 18 and 19.

The wall defining the parallel notches 18 and 19 and which are formed adjacent each end of the tie rod are arcuately formed. Tie rod coupling means 50 on its upper surface has an arcuate recess 56 formed normal to notch 46. The arcuate recess 56 permits the arcuate wall of the respective parallel notches 18, 19, 65 and to contact tie rod coupling means at any angle with respect to the tie rod passing through the concrete forms F" illustrated in FIGS. 7 through 9. Also, formed in tie rod coupling means 50 is a recess 57 having dimensions substantially equal to the outside dimensions of camming head 64 of tie rod 62. Formed at the outer lips 48 of notch 46 are camming surfaces so that when wedge 42 is mounted on the form as seen in FIG. 11 tie rod coupling means 50 will automatically slip over camming head 64 to releasably lock tie rod 62 in fixed position.

Wedge 42 has increased strength clue to the construction of tie rod coupling means 50. When tie rod 12 or 62 is mounted in fixed position on the forms as illustrated in FIGS. 7 and 8 the forces exerted by the concrete against tie rod 12 or 62 would tend to shear the ends of the tie rod or tend to deform wedge 42 so that it would fail. However, by providing the tie rod 62 with arcuate wall surfaces 71 the forces exerted on the tie rod are transmitted over the entire mass of tie rod coupling means 50 as illustrated more clearly in FIGS. II and 12. It is possible therefore to increase the load of the wedge by providing the structure of tie rod coupling means 50.

FIG. 5 and 6 illustrate another embodiment of a resuable tie assembly 60 for concrete forms capable of being disassembled after use in accordance with the invention herein. Tie assembly 60 comprises tie rod 62 having a flanged head portion 64 formed at end 63 and at the other end 61 is a pair of parallel slots 65. A tubular metal member 68 having a pair of parallel slots 70 is formed at end 69 and at the other end a threaded portion 72 is formed and is adapted to threadably mount internal spreader means 80 thereto. Tubular member 68 is slidably mounted on tie rod 62 so that parallel slots 70 are positioned adjacent the flanged head portion 64. Tubular member 68 is pennanently retained on tie rod 62 by forming diametrically opposed projections 66 after tubular member 68 has been slidably mounted on rod 62. Projections 66 are formed similar to projections 14 and 15 of rod 12 as described in FIG. I. A similar pair of projections 67 are formed and spaced a distance from threaded end 72 of pipe 68 such that when internal spreader means 80 is mounted thereon, as illustrated in FIG. 6, a desired distance for maintaining forms is obtained as illustrated most clearly in FIGS. 7 through 9. Internal spreader means 80 has mounted at one end a frustro conical cone 82 similar in design and formed of similar material to frustro conical cones 22 and 23 of FIG. 1. Embedded in base 81 of cone 82 is threaded nut 83 adapted to receive in threaded engagement threaded end 72 of tubular member 68. At the other end of internal spreader means 80 is a removable frustro conical cone 84 similar in configuration to frustro conical cones 22 and 23 of FIG. 1. Embedded in the base of cone 84 is washer 37 similar to the washer 36 of FIGS. 3 and 4 but preferably without slots. Internal sleeve means 80 includes sleeve 86 and forms a passage for tie rod 62. Sleeve 86 is made of an elastic material such as natural or synthetic rubber.

Illustrated in FIG. 8, tie assembly 60 is mounted in position to forms F. Also illustrated mounted in position on tie rod 62 is steel wedge 42. Tie rod coupling means 50 is illustrated having the surfaces defining parallel slots 65 mounted therein while at the other end the surfaces defining parallel slots 70 of tubular member 68 are mounted to slot 44 of wedge 42 as illustrated in FIGS. 11 and 12. Tie rod coupling means 50 is provided with a recess 57 which is of a size to receive a portion of camming head 64 of rod 62. The surfaces defining parallel slots 70 slidably engage the surfaces defining longitudinally extending slot 44. Thus, when tie assembly 60 is mounted in position, as shown in FIGS. 8, 11 and I2, tie rod 62 is incapable of lateral movement since the parallel slots 65 and 70 are locked in wedge 42 thereby maintaining forms F a predetermined distance defined by the length of internal spreader means 80. Also, by employing the wedge 42, the assembly 60 does not necessarily require mounting through forms F" in a position normal to forms F but may be skew thereto. This is possible since the surfaces defining parallel slots 65 and are formed having arcuate walls 71 and 72'. Similar arcuate walls are formed in parallel slots 18 and 19 of rod 12. Further, by providing arcuate walls in the parallel slots of the embodiments of FIGS. 1 and 5 and the arcuate recess 56 of tie rod coupling means 50 it is possible to maintain the lateral pressures created by concrete being poured into the space between the forms and to increase the rated load of the wedge without the necessity of increasing the mass of the wedge or tie rod.

In practice, the process for erecting and stripping forms is illustrated in FIGS. 7 through 9. As indicated above, the tie assembly depicted in FIGS. 7 through 9 illustrates the assembly of FIG. 5. Thus, in describing the erection and stripping of forms F illustrated in FIGS. 7 through 9 the tie assembly of FIG. 5 will be described. Tie assembly 60 is disassembled by unthreading tubular member 68 from internal spreader means which is removed from tie rod 62. Tie rod 62 is passed through an opening in form F, then internal spreader means 80 is slidably mounted on tie rod 62 so that only a short distance of tie rod 62 extends beyond removable cone 84 of internal spreader means 80. Then, after all of the tie rods that are to be employed for form F" are similarly mounted therein the closing form is mounted by manipulating tie rod 62 into corresponding openings of the second form. Tie rod 62 is then mounted in position by the assembly of steel wedge 42 the parallel members or wallers as illustrated in FIG. 8 and as shown in enlarged elevational view of FIGS. 11 and 12. Tie rod 62 is locked in position by mounting the ends of the tie rod as described for FIGS. 11 and 12. Wedge 42 is held in position simply by a wedging action or, for example, by using a nail through the openings 49 provided in wedge 42 as shown in FIG. 10.

After the concrete has been poured, the nails are removed from wedge 42 and the ends of the tie rod 62 are unlocked by simply removing the steel wedge from the forms. Tie rod 62 is released from tie rod coupling means 50 and is retracted to the point where projections 66 of tie rod 62 contact the end of tubular member 68. When tie rod 62 is removed to the point where projection 66 are contacted by tubular member 68, tubular member 68 is unthreaded from the threaded nut 83 embedded in cone 82. Then tie rod 62 together with tubular member 68 is removed. Tie rod 62 is also removed in FIG. 9 so that only internal spreader means 80 remains embedded in the concrete. Forms F are then stripped from the concrete in the usual fashion exposing cones 82 and 84. Also projections 82' and 84 formed on cones 82 and 84 prevent rotation of the cones when removing tie rod 62 as described above. Cone 82 is grasped and by simply stretching elastomeric sleeve 86 the bond holding the elastomeric sleeve in the concrete is broken and is then easily removed therefrom. Then by simply grasping cone 84 embedded on the other side of the concrete it is removed and reassembled as explained above. The passage made by elastomeric sleeve means is plugged in the usual fashion.

It is obvious from the foregoing that a reusable tie assembly has been disclosed and it is easily and quickly disassembled for removal from the concrete after a forming operation and can be reassembled for subsequent reuse. Also, the resuable tie assembly of the invention herein can be mounted in position even though the tie rod is not exactly normal to the surface of the form and the wedge means employed permits mounting the tie rod in fixed position even though it is skewed to the surface of the form.

We claim:

1. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable coupling means at its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having embedded therein at its base an annular metal ring defining the releasable coupling means, the annular metal ring being formed having diametrically opposed slots and depending from the base of each slot are stop means capable of engaging the means defining surfaces formed on the rod.

2. The internal spreader of claim 1 wherein one of the frustro conical cones is securely mounted to an end of the elongated elastomeric sleeve.

3. The internal spreader of claim 2 wherein the other frustro conical cone is removably mounted to the other end of the elongated elastomeric sleeve.

4. The internal spreader of claim 1 wherein each cone has a raised annular rim formed about the base thereof adapted to sealingly engage a concrete form to seal the base of the cone against the form.

5. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a rigid but yieldable frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable coupling means at its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having embedded therein at its base an annular metal ring defining the releasable coupling means, the annular metal ring being internally threaded.

6. The internal spreader of claim 5 wherein one of the frustro conical cones is securely mounted to an end of the elongated elastomeric sleeve.

7. The internal spreader of claim 6 wherein the other frustro conical cone is removably mounted to the other end of the elongated elastomeric sleeve.

8. The internal spreader of claim 5 wherein each cone has a raised annular rim fonned about the base thereof adapted to sealingly engage a concrete form to seal the frustro of the cone against the form.

9. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a rigid but yieldable frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable metal coupling means embedded in its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having at least one projection formed radially about the lateral surface thereof and adjacent the inner end thereof so as to provide stop means to prevent rotation of each cone when retracting or removing the tie rod therefrom.

10. The internal spreader of claim 9 wherein each cone has a raised annular rim fon'ned about the base thereof adapted to sealingly engage a concrete form to seal the base of the cone against the fonn. 

1. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable coupling means at its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having embedded therein at its base an annular metal ring defining the releasable coupling means, the annular metal ring being formed having diametrically opposed slots and depending from the base of each slot are stop means capable of engaging the means defining surfaces formed on the rod.
 2. The internal spreader of claim 1 wherein one Of the frustro conical cones is securely mounted to an end of the elongated elastomeric sleeve.
 3. The internal spreader of claim 2 wherein the other frustro conical cone is removably mounted to the other end of the elongated elastomeric sleeve.
 4. The internal spreader of claim 1 wherein each cone has a raised annular rim formed about the base thereof adapted to sealingly engage a concrete form to seal the base of the cone against the form.
 5. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a rigid but yieldable frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable coupling means at its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having embedded therein at its base an annular metal ring defining the releasable coupling means, the annular metal ring being internally threaded.
 6. The internal spreader of claim 5 wherein one of the frustro conical cones is securely mounted to an end of the elongated elastomeric sleeve.
 7. The internal spreader of claim 6 wherein the other frustro conical cone is removably mounted to the other end of the elongated elastomeric sleeve.
 8. The internal spreader of claim 5 wherein each cone has a raised annular rim formed about the base thereof adapted to sealingly engage a concrete form to seal the frustro of the cone against the form.
 9. An internal spreader means adapted to be positioned on a retractable and reusable tie rod and adapted to be positioned between concrete forms to maintain the forms a predetermined distance apart, said spreader means including an elongatable elastomeric sleeve for providing a passage for the tie rod so that after the concrete has been poured the tie rod may be retracted and removed from the internal spreader while the forms are still in place, a rigid but yieldable frustro conical cone at each end of the sleeve, each cone having an outer larger base and an inner smaller end, each cone having releasable metal coupling means embedded in its base for engaging the tie rod in one position and for disengaging the tie rod in a second position from each other while the forms are still in place whereby the spreader means is removable from the concrete without damage to the internal spreader means or the concrete, each cone having at least one projection formed radially about the lateral surface thereof and adjacent the inner end thereof so as to provide stop means to prevent rotation of each cone when retracting or removing the tie rod therefrom.
 10. The internal spreader of claim 9 wherein each cone has a raised annular rim formed about the base thereof adapted to sealingly engage a concrete form to seal the base of the cone against the form. 